There are people standing in line who have been there since 10.30pm the night before and they are all set to buy into the avant garde world of Maison Martin Margiela, a label specialising in rather unconventional clothes. On sale are jackets with odd pointy shoulders, fabrics used inside out, coats and jeans cut in gargantuan oversized proportions. It is not for the uninitiated.
As a group of shoppers sweep into the Regent Street store - politely at first but soon madly running up escalators - the H&M website crashes. The first 20 customers allowed to shop from the women's collection in a specially cordoned off area, meanwhile, begin by pouncing on "sweetie wrapper" clutches in silver or metallic purple; leaving TV camera crews and photographers blinded by a £34.99 reflective handbag.
A leather biker jacket with statement shoulders, which originally appeared in the spring/summer 2012 mainline Margiela collection was another early crowd-pleaser, while £29.99 mirrorball leggings of spring/summer 2009 were also popular.
The buzz around this particular range started in June when the initial announcement of the partnership was released. It has since been backed by an exhaustive marketing campaign.
Last month, a blockbuster party was staged in New York complete with dance performances choreographed by Anne Teresa De Keersmaeker. Earlier this week, a series of marches by Margiela "demonstrators" were staged in cities across the world. Groups of men and women sporting white aprons with trademark Margiela numbering on them and brandishing placards were said to be taking part in a "silent manifesto". This off-beat concept is very on-message for the Paris-based catwalk brand.
Since the first H&M collaboration with Karl Lagerfeld in 2004, the launch of each capsule designer range has become a major fashion event. For a brand such as Margiela, which might be well known in fashion circles but is hardly mainstream, it is a fantastic opportunity to reach a wider audience, while for the H&M customer, these ranges have become both collectible and highly sellable, at inflated prices, on eBay.
"I've never heard of him [Margiela] but I just always buy things from the H&M designer ranges," said Lisa Hyatt, from Notting Hill, who had bought £900 worth of womenswear, including a coat made from a duvet.
Bella Ting, 25, spent £1,612.77, but also claimed not to really know anything about the high-end fashion label. "My sister is a fan," she said. "It's quite odd. It's a bit like the sort of thing you might see people wearing on Brick Lane isn't it?"
But for hardcore fans, who ordinarily cannot afford the expensive catwalk creations, this is their chance to own a slice of their chosen designer.
"I've been a fan for a few years but I could never really afford it until now," said Matt Evans, 27, from north London, who spent around £330 on a faux fur coat and some boots.
Eleonora Sacco, 27, who had queued since 5am, has admired the brand over the past decade. She bought a black dress, a metallic clutch and bracelet, all for around £130. "I like that it's quite strange and you can't find it everywhere," she said.
Set up by Martin Margiela in 1988 in Paris, the Maison Martin Margiela label is now owned by Diesel, with Margiela reportedly leaving the brand in 2009.
All the clothes being sold by H&M are original designs from the label and each piece comes with a tag explaining which collection it first appeared in. The Margiela collaboration with H&M follows on from other past hits with designers including Stella McCartney, Versace and Lanvin.
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image: © John Mitchell